U.S. patent application number 14/137405 was filed with the patent office on 2015-06-25 for vehicle brake transmission.
This patent application is currently assigned to Automotive Research & Testing Center. The applicant listed for this patent is Automotive Reserach & Testing Center. Invention is credited to Jiun-Jie Chen, Shih-Chieh Huang, Fu-Xian Sun.
Application Number | 20150175143 14/137405 |
Document ID | / |
Family ID | 53399187 |
Filed Date | 2015-06-25 |
United States Patent
Application |
20150175143 |
Kind Code |
A1 |
Sun; Fu-Xian ; et
al. |
June 25, 2015 |
Vehicle Brake Transmission
Abstract
A vehicle brake transmission includes a housing unit, a motor
assembly, and a speed reduction unit. The housing unit includes a
ring gear disposed around a first axis. The motor assembly includes
a motor, and a worm rod extending along a second axis perpendicular
to the first axis. The speed reduction unit is disposed in the
housing unit, and includes a driving member, a planet carrier, and
a plurality of planet gears. The driving member includes a worm
wheel meshing with the worm rod, and a sun gear centered at the
first axis and meshing with the planet gears. The planet carrier
includes an input shaft connected to a caliper device. The motor
drives rotation of the worm shaft, the driving member, the planet
gears, and the input shaft, so as to activate the caliper
device.
Inventors: |
Sun; Fu-Xian; (Changhua
County, TW) ; Chen; Jiun-Jie; (Changhua County,
TW) ; Huang; Shih-Chieh; (Changhua County,
TW) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Automotive Reserach & Testing Center |
Changhua County |
|
TW |
|
|
Assignee: |
Automotive Research & Testing
Center
Changhua County
TW
|
Family ID: |
53399187 |
Appl. No.: |
14/137405 |
Filed: |
December 20, 2013 |
Current U.S.
Class: |
74/89.16 |
Current CPC
Class: |
F16D 2125/50 20130101;
B60T 13/746 20130101; F16D 55/226 20130101; F16H 1/28 20130101;
F16H 1/16 20130101; F16D 2125/52 20130101; F16H 19/02 20130101;
F16D 2121/24 20130101; F16D 65/183 20130101; Y10T 74/188
20150115 |
International
Class: |
B60T 13/74 20060101
B60T013/74; F16H 19/02 20060101 F16H019/02 |
Claims
1. A vehicle brake transmission adapted for activating a caliper
device, said vehicle brake transmission comprising: a housing unit
including a ring gear disposed around a first axis; a motor
assembly mounted to said housing unit and including a motor, and a
worm shaft driven by said motor to rotate about a second axis
perpendicular to said first axis; and a speed reduction unit
disposed in said housing unit and including a driving member driven
by said worm shaft of said motor assembly to rotate about said
first axis, a planet carrier located under said driving member and
disposed pivotally in said housing unit, and a plurality of planet
gears meshing with said ring gear of said housing unit, said
driving member including a worm wheel meshing with said worm shaft,
and a sun gear connected integrally with said worm wheel, extending
along said first axis, and meshing with said planet gears, said
planet carrier including an input shaft adapted to be connected
with said caliper device and extending along said first axis;
wherein said motor is operable to drive rotation of said worm
shaft, said driving member, said planet gears, and said input shaft
of said planet carrier, so as to activates said caliper device.
2. The vehicle brake transmission as claimed in claim 1, wherein
said housing unit further includes a first bearing disposed along
said first axis, and a second bearing disposed along said second
axis, said planet carrier further including a position limiting
hole formed in a center thereof and centered at said first axis,
said driving member further including a pivot shaft disposed at a
top end thereof and extending through said first bearing along said
first axis, and a position limiting shaft disposed at a bottom end
of said driving member and extending through said position limiting
hole along said first axis, said worm shaft having an end extending
through said second bearing.
3. The vehicle brake transmission as claimed in claim 2, wherein
said housing unit further includes a housing body disposed around
said input shaft and permitting said worm shaft and said speed
reduction unit to be disposed therein, and a top cover connected to
and disposed above said housing body.
4. The vehicle brake transmission as claimed in claim 3, wherein
said housing body includes a bottom wall perpendicular to said
first axis, a primary surrounding wall extending upwardly from an
outer periphery of said bottom wall to define a primary chamber,
and a secondary surrounding wall connected to said primary
surrounding wall and disposed around said second axis to define a
secondary chamber, said top cover having a cover body perpendicular
to said first axis and covering removably said housing body, and a
groove formed in a central portion of said cover body and
permitting said first bearing to be received therein, said speed
reduction unit being disposed within said primary chamber, said
worm shaft and said second bearing being disposed within said
secondary chamber, said ring gear being disposed on an inner
surface of said primary surrounding wall.
5. The vehicle brake transmission as claimed in claim 4, wherein
said housing unit further includes a plurality of stop blocks
spaced apart from each other and disposed around said first axis
for limiting rotational angle of said planet carrier.
6. The vehicle brake transmission as claimed in claim 5, wherein
said stop blocks are made of a soft material.
7. The vehicle brake transmission as claimed in claim 5, wherein
said planet carrier further includes a plate body having a side
surface connected to said input shaft, a plurality of mounting pins
disposed on an opposite side surface of said plate body and
permitting said planet gears to be sleeved respectively and
rotatably thereon, and a plurality of projections disposed on an
outer periphery of said plate body and each contactable with and
confined between two adjacent ones of said stop blocks.
8. The vehicle brake transmission as claimed in claim 2, wherein
said housing unit further includes a housing adapted to be disposed
removably on the caliper device, said housing including a top wall
perpendicular to said first axis, a recess formed in said top wall,
a primary surrounding wall extending downwardly from an outer
periphery of said top wall to define a primary chamber, and a
secondary surrounding wall connected to said primary surrounding
wall to define a secondary chamber, said speed reduction unit being
disposed within said primary chamber, said first bearing being
disposed within said recess, said worm shaft and said second
bearing being disposed within said secondary chamber, said ring
gear being disposed on an inner surface of said primary surrounding
wall.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to a transmission, and more
particularly to a vehicle brake transmission.
[0003] 2. Description of the Related Art
[0004] Referring to FIG. 1, a conventional brake transmission
disclosed in Chinese Patent Publication No. 101031459 includes two
belt pulleys 11 and a belt 12 that are used to transfer rotation of
a motor 13 to a planetary gear speed reduction mechanism 14 to
thereby activate a braking device 15. The conventional brake
transmission suffers from the following disadvantages:
[0005] 1. The transmission has a large number of components,
thereby increasing the manufacturing and assembly costs.
[0006] 2. After a long time period of use, the tightness of the
belt 12 becomes poor. That is, the transmission is not durable.
[0007] 3. Since it is necessary to associate the transmission with
a specifically designed caliper, the transmission is difficult to
be modified quickly.
SUMMARY OF THE INVENTION
[0008] The object of this invention is to provide a vehicle brake
transmission that has the advantages of anti-reverse, less
components, simple structure, low costs, easy assembly, high
speed-reduction ratio, quick modification, convenient to use with a
caliper, and high reliability.
[0009] According to this invention, a vehicle brake transmission
includes a housing unit, a motor assembly, and a speed reduction
unit. The housing unit includes a ring gear disposed around a first
axis. The motor assembly includes a motor, and a worm rod extending
along a second axis perpendicular to the first axis. The speed
reduction unit is disposed in the housing unit, and includes a
driving member, a planet carrier, and a plurality of planet gears.
The driving member includes a worm wheel meshing with the worm rod,
and a sun gear centered at the first axis and meshing with the
planet gears. The planet carrier includes an input shaft connected
to a caliper device. The motor drives rotation of the worm shaft,
the driving member, the planet gears, and the input shaft, so as to
activate the caliper device.
[0010] The vehicle brake transmission of this invention is
advantageous in that, through cooperation of the worm rod and the
worm wheel, when used for a long time period, power can be
transmitted steadily. Furthermore, by virtue of the mechanical
characteristics of the worm rod and the worm wheel, transmission of
power cannot be reversed, and the speed reduction ratio can be
increased. Further, since less components are used for power
transmission, the vehicle brake transmission is simple in
structure, and is easy to assemble. In addition, this invention is
easy to be mounted to various caliper devices, and thus can be
modified quickly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] These and other features and advantages of this invention
will become apparent in the following detailed description of the
preferred embodiments of this invention, with reference to the
accompanying drawings, in which:
[0012] FIG. 1 is a sectional view of a conventional brake
transmission disclosed in Chinese Patent Publication No.
101031459;
[0013] FIG. 2 is a perspective view of the first preferred
embodiment of a vehicle brake transmission according to this
invention;
[0014] FIG. 3 is an exploded perspective view of the first
preferred embodiment;
[0015] FIG. 4 is a schematic perspective view of the first
preferred embodiment, wherein a caliper device, a top cover of a
housing unit, a driving member of a speed reduction unit, and a
plurality of planet gears are removed;
[0016] FIG. 5 is a sectional view taken along line V-V in FIG.
2;
[0017] FIG. 6 is an enlarged view of a portion of FIG. 5;
[0018] FIG. 7 is a partly exploded perspective view illustrating
how to assemble the first preferred embodiment;
[0019] FIG. 8 is a perspective view of the second preferred
embodiment of a vehicle brake transmission according to this
invention; and
[0020] FIG. 9 is a sectional view taken along line IX-IX in FIG.
8.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0021] Before the present invention is described in greater detail
in connection with the preferred embodiments, it should be noted
that similar elements and structures are designated by like
reference numerals throughout the entire disclosure.
[0022] Referring to FIGS. 2, 3, 5, and 6, the first preferred
embodiment of a vehicle brake transmission according to this
invention is adapted to activate a caliper device 10. The caliper
device 10 includes a support seat 101, a motion transmitting rod
102 disposed on the support seat 101, and a disk driving rod 103
driven by the motion transmitting rod 102 to move a brake disk (not
shown). The vehicle brake transmission includes a housing unit 2, a
motor assembly 3, and a speed reduction unit 4.
[0023] The housing unit 2 includes a housing body 21 disposed on
the support seat 101 of the caliper device 10, a top cover 22
connected removably to and disposed above the housing body 21, a
ring gear 23 disposed around a first axis (L1) and disposed on the
housing body 21, a first bearing 24 disposed on the top cover 22
along the first axis (L1), a second bearing 25 disposed on the
housing body 21 along a second axis (L2), and a plurality of
spaced-apart stop blocks 26 disposed on the housing body 21 and
around the first axis (L1). In this embodiment, the second axis
(L2) is perpendicular to the first axis (L1), and the stop blocks
26 are made of a soft material for cushioning purposes.
[0024] The housing body 21 includes a bottom wall 211 perpendicular
to the first axis (L1) and disposed removably on the support seat
101, a primary surrounding wall 213 extending upwardly from an
outer periphery of the bottom wall 211 to define a primary chamber
212, and a secondary surrounding wall 215 connected integrally to
the primary surrounding wall 213 and disposed around the second
axis (L2) to define a secondary chamber 214 in spatial
communication with the primary chamber 212. The speed reduction
unit 4 is disposed within the primary chamber 212. The second
bearing 25 is disposed within the secondary chamber 214. The ring
gear 23 is disposed on an inner surface of the primary surrounding
wall 213.
[0025] The top cover 22 has a cover body 221 in the form of a
horizontal plate perpendicular to the first axis (L1) for covering
removably the housing body 21, and a groove 222 formed in a central
portion of the cover body 221 and permitting the first bearing 24
to be received therein.
[0026] The motor assembly 3 is mounted removably to the housing
unit 2, and includes a motor 31, and a worm shaft 32 disposed
within the secondary chamber 214, having an end extending through
the second bearing 25 along the second axis (L2), and driven by the
motor 31 to rotate about the second axis (L2).
[0027] The speed reduction unit 4 includes a driving member 41
driven by the worm shaft 32 of the motor assembly 3 to rotate about
the first axis (L1), a planet carrier 42 located under the driving
member 41 and disposed pivotally in the housing unit 2, and a
plurality of planet gears 43 disposed between the driving member 41
and the planet carrier 42 and meshing with the ring gear 23. In
this embodiment, the speed reduction unit 4 is a first-stage
planetary gear mechanism. Alternatively, the speed reduction unit 4
may be a multi-stage planetary gear mechanism.
[0028] The driving member 41 includes: a worm wheel 411 meshing
with the worm shaft 32; a sun gear 412 connected with and disposed
under the worm wheel 411, extending along the first axis (L1), and
meshing with the planet gears 43; a pivot shaft 413 disposed at a
top end of the driving member 41, connected integrally to and
disposed above the worm wheel 411, and extending through the first
bearing 24 along the first axis (L1); and a position limiting shaft
414 disposed at a bottom end of the driving member 41, connected
integrally to and disposed under the worm wheel 411, and extending
along the first axis (L1).
[0029] With further reference to FIG. 4, the planet carrier 42
includes an input shaft 421 connected with the motion transmitting
rod 102 of the caliper device 10 and extending through the bottom
wall 211 of the housing body 21 along the first axis (L1) (i.e.,
the housing body 21 is disposed around the input shaft 421), a
plate body 422 having a side surface connected to the input shaft
421, a plurality of mounting pins 423 disposed on an opposite side
surface of the plate body 422 and permitting the planet gears 43 to
be sleeved respectively and rotatably thereon, a plurality of
projections 424 disposed on an outer periphery of the plate body
422 and each contactable with and confined between two adjacent
stop blocks 26, and a position limiting hole 425 formed in a center
of the plate body 422 and centered at the first axis (L1) for
permitting the position limiting shaft 414 to extend therethrough.
In this embodiment, the input shaft 421 has a concaved camming
surface 4211 for contact with a round end of the motion
transmitting rod 102, in such a manner that rotation of the input
shaft 421 results in swinging movement of the motion transmitting
rod 102 and, thus, movement of the disk driving rod 103. Since such
a motion conversion is not pertinent to this invention, further
description thereof will be omitted. It should be noted that, due
to cooperation of the stop blocks 26 with the projections 424, the
rotational angle of the planet carrier 42 is limited so as to
prevent rotation of the input shaft 421 by an excessively large
angle.
[0030] In this embodiment, the ring gear 23 is formed integrally on
the primary surrounding wall 213 of the housing body 21, the worm
shaft 32 and an output shaft 311 of the motor 31 are formed as one
piece, the sun gear 412 and the worm wheel 411 are formed as one
piece, and the plate body 422 and the input shaft 421 are formed as
one piece. Alternatively, the ring gear 23 may be disposed
removably on the primary surrounding wall 213 of the housing body
21, the worm shaft 32 and an output shaft of the motor 31 may be
two separate members, the sun gear 412 and the worm wheel 411 may
be two separate members, and the plate body 422 and the input shaft
421 may be two separate members.
[0031] The motor 31 is operable to drive rotation of the worm shaft
32 about the second axis (L2) and, thus, rotation of the worm wheel
411 of the driving member 41 about the first axis (L1). Rotation of
the worm wheel 411 and the sun gear 412 is transferred to the
planet carrier 42 through the planet gears 43, so as to rotate the
input shaft 421 of the planet carrier 42 about the first axis (L1),
thereby moving the motion transmitting rod 102 and the disk driving
rod 103 to activate the brake disk. The worm shaft 32 cooperates
with the worm wheel 411 to constitute a worm gear device. As
compared to the above-mentioned conventional belt and pulley
arrangement, the worm gear device has less components, is more
durable, and allows the brake transmission to be modified more
quickly. Furthermore, the worm gear device can have a higher speed
reduction ratio, and thus is suitable for use in a narrower space.
In a situation where a power failure is encountered, the worm gear
device has an anti-reverse function so that reverse rotation of the
motor 31 can be prevented.
[0032] With particular reference to FIG. 7, during assembly, the
housing body 21 and the planet carrier 42 are mounted to the
caliper device 10, and the top cover 22 and the driving member 41
are assembled together. Subsequently, the planet gears 43 are
sleeved respectively on the mounting pins 423. Thereafter, an
assembly of the top cover 22 and the driving member 41 are mounted
to the housing body 21. Finally, the motor assembly 3 is mounted to
the housing body 21. As such, the vehicle brake transmission of
this invention has a simple structure, and can be assembled
quickly.
[0033] FIGS. 8 and 9 show the second preferred embodiment of a
vehicle brake transmission according to this invention. Unlike the
first preferred embodiment, the housing unit 2 includes only a
housing 21' disposed removably on the caliper device 10. The
housing 21' includes atop wall 211' perpendicular to the first axis
(L1), a recess 212' formed in the top wall 211', a primary
surrounding wall 214' extending downwardly from an outer periphery
of the top wall 211' to define a primary chamber 213', and a
secondary surrounding wall 216' connected to the primary
surrounding wall 214' to define a secondary chamber 215' in spatial
communication with the primary chamber 213'. The speed reduction
unit 4 is disposed within the primary chamber 213'. The first
bearing 24 is disposed within the recess 212'. The worm shaft 32
and the second bearing 25 are disposed within the secondary chamber
215. The ring gear 23 is disposed on an inner surface of the
primary surrounding wall 214'.
[0034] To sum up, the vehicle brake transmission of this invention
has the following advantages: [0035] 1. As compared to the design
of the belt 12 (see FIG. 1) and the belt pulleys 11 (see FIG. 1) of
the above-mentioned prior art, through cooperation of the worm rod
32 and the worm wheel 411, when used for a long time period, power
can be transmitted steadily. [0036] 2. By virtue of the mechanical
characteristics of the worm rod 32 and the worm wheel 411, when the
power supply is cut off, the reverse rotation of the motor 31
driven by the caliper device 10 can be prevented. Furthermore, an
assembly of the worm rod 32 and the worm wheel 411 can have a high
speed-reduction ratio, so as to allow a more than three-stage speed
reduction mechanism to be modified into a two-stage speed reduction
mechanism in a limited space, thereby reducing the number of the
components used for power transmission. For example, such
components may include only the driving member 41 and two planet
gears 43. As such, the component number of this invention is
smaller than that of any existing integrated caliper type electric
parking brake (IEPB). [0037] 3. Since this invention has a less
component number and a simple structure, and is easy to assemble,
the assembly time and the manufacturing costs can be reduced
effectively. Furthermore, this invention is easy to be mounted to
various caliper devices, and thus can be modified quickly. [0038]
4. The driving member 41 is unitary, and includes the worm wheel
411, the sun gear 412, the pivot shaft 413, and the position
limiting shaft 414. That is, the structure of the driving member 41
is new.
[0039] With this invention thus explained, it is apparent that
numerous modifications and variations can be made without departing
from the scope and spirit of this invention. It is therefore
intended that this invention be limited only as indicated by the
appended claims.
* * * * *